The present invention relates in general to mechanisms for electrically coupling two components, and in specific to a ribbon cable, an electrical connector, and a temporarily engageable/disengageable mechanism for electrically coupling microcomponents.
Extraordinary advances are being made in microelectronic devices and MicroElectroMechanical (xe2x80x9cMEMxe2x80x9d) devices, which comprise integrated micromechanical and microelectronic devices. The terms xe2x80x9cmicrocomponentxe2x80x9d and xe2x80x9cmicrodevicexe2x80x9d will be used herein generically to encompass microelectronic components, as well as MEMs components. A need exists in the prior art for a mechanism for electrically coupling microcomponents.
In the prior art, integrated circuits (xe2x80x9cICsxe2x80x9d) are commonly implemented with a microcomponent (e.g., a MEMs component) hard wired to a bond pad (e.g., with electrical traces on the circuit). That is, the wiring electrically coupling microcomponents within an IC of the prior art is physically attached to the substrate and is not releasable therefrom. To electrically couple the microcomponents of one IC to those of another IC, for example, external wires are coupled from one IC to the bond pads of another IC. The bond pads provide a connection point for a wire typically 25 microns in diameter. A solder bump may be utilized, which is a ball of solder that is about 75 microns in diameter. Turning to FIG. 10, an example of such a prior art implementation is shown. In FIG. 10, a one centimeter die site 10 (which may be referred to as a xe2x80x9cchipxe2x80x9d) is implemented having one or more MEMs components 12 included thereon. It should be understood that the die site may be any of various sizes commonly implemented in the prior art, but for illustrative purposes, a one centimeter die site is described in conjunction with FIG. 10. As further shown, the die site 10 includes bond pads 14, which are each typically approximately 50 to 100 microns in size. The MEMs components 12 are xe2x80x9chard wiredxe2x80x9d to the bond pads 14 with electrical traces 16. Thereafter, the MEMs components 12 may be electrically coupled to off-chip devices (i.e., devices off die site 10) through coupling wires to the appropriate bond pads.
As is well known in the prior art, the chip 10 is typically placed in a xe2x80x9cchip carrier,xe2x80x9d which is the package for the chip. Thus, the entire one centimeter die 10 is placed in a package which provides wires to the outside world. Typically, a machine called a xe2x80x9cwire bonderxe2x80x9d connects each pad of the chip 10 to an appropriate pin on the package using wires 18. Wires 18 are each approximately 25 microns in size. Given that a MEMs component may be only 100 microns (or smaller) in size, the external wires 18 used to couple the bond pads to a pin on the package are relatively large in comparison with MEMs components 12.
The above-described prior art technique of coupling MEMs components of a chip to off-chip devices has many characteristics that are often undesirable in implementing MEMs components. First, the individual MEMs components are permanently hard-wired in a manner that does not permit the individual MEMs components to move (e.g., rotate and/or translate along a path) as may be desired for some implementations. Additionally, a disproportionately large amount of area is consumed by the wiring for coupling the MEMs components. For example, each external wire 18 of FIG. 10 is approximately 25 microns in size, wherein an individual MEM component 12 may be 100 microns (or less) in size. Accordingly, the wiring required for coupling the MEMs components to off-chip devices may consume more area than is required for the MEMs components themselves. As a result, the prior art technique of coupling microcomponents (e.g., MEMs components) does not allow for individual components to be electrically coupled to other devices in a flexible manner such that the components may maintain an electrical coupling as the components move (e.g., rotate and/or translate in some direction) relative to each other. Furthermore, the prior art technique of coupling microcomponents does not allow for individual components to be temporarily electrically coupled to another component in a manner such that the components may be electrically engaged for a period of time and then electrically disengaged for a period of time.
In view of the above, a desire exists for an electrical coupling mechanism suitable for electrically coupling microcomponents. A further desire exists for a relatively small-scale electrical coupling mechanism that is not disproportionately large in relation to the microcomponents being coupled. Still a further desire exists for a flexible electrical coupling mechanism that is capable of adapting to various positions to enable microcomponents to be flexibly coupled. For example, a desire exists for a flexible electrical coupling mechanism that enables microcomponents to maintain an electrical coupling as the components move (e.g., rotate and/or translate in some direction) relative to each other. Yet a further desire exists for an electrical coupling mechanism that enables individual components to be electrically engaged for a period of time and then electrically disengaged for a period of time. That is, a desire exists for an electrical coupling mechanism that may be utilized to engage and disengage a component to provide an electrical coupling in a desirable manner.
These and other objects, features and technical advantages are achieved by a system, apparatus, and method which enable microcomponents to be electrically coupled in a desirable manner. More specifically, electrical coupling mechanisms are disclosed, which are suitable for providing an electrical coupling between two or more microcomponents. One electrical coupling mechanism provided herein, which may be utilized to provide a flexible coupling between two or more microcomponents, is a ribbon cable. Such a ribbon cable may include one or more electrically isolated conducting xe2x80x9crows,xe2x80x9d which may enable communication of electrical signals between two or more microcomponents coupled to such ribbon cable. An electrical connector is also provided herein, which is suitable for electrically coupling two or more microcomponents. Such an electrical connector may be utilized to couple a ribbon cable to a microcomponent or it may be utilized to directly couple two microcomponents in a manner that enables electrical communication therebetween. Furthermore, a xe2x80x9cZ clampxe2x80x9d electrical connector is provided which allows for an engageable/disengageable electrical connection to be achieved between two or more microcomponents.
The electrical coupling mechanisms of the present invention may be integrated within a microcomponent to enable the microcomponent to be electrically coupled to another microcomponent. For example, a MEMs component may be fabricated having an electrical connector (e.g., ribbon cable, connector, and/or Z clamp connector) included therewith to enable the MEMs component to obtain a desired electrical coupling to one or more other MEMs components. Furthermore, the electrical coupling mechanisms may be implemented as an integrated part between two or more microcomponents. For example, two or more MEMs components may be fabricated having an electrical coupling mechanism as an integrated component that electrically couples such two or more components. Alternatively, the electrical coupling mechanisms of the present invention may be implemented as stand-alone mechanisms that may then be used to provide a desired electrical coupling between two or more microcomponents.
The electrical coupling mechanisms of the present invention may be fabricated utilizing any of various fabrication techniques, including, as examples, those fabrication processes disclosed in U.S. Pat. No. 4,740,410 issued to Muller et al. entitled xe2x80x9cMICROMECHANICAL ELEMENTS AND METHODS FOR THEIR FABRICATION,xe2x80x9d U.S. Pat. No. 5,660,680 issued to Chris Keller entitled xe2x80x9cMETHOD FOR FABRICATION OF HIGH VERTICAL ASPECT RATIO THIN FILM STRUCTURES.xe2x80x9d U.S. Pat. No. 5,645,684 issued to Chris Keller entitled xe2x80x9cMULTILAYER HIGH VERTICAL ASPECT RATIO THIN FILM STRUCTURES,xe2x80x9d as well as the fabrication process disclosed in concurrently filed and commonly assigned U.S. patent application Ser. No. 09/569,330 entitled xe2x80x9cMETHOD AND SYSTEM FOR SELF-REPLICATING MANUFACTURING STATIONS,xe2x80x9d the disclosure of which is hereby incorporated herein by reference. However, other fabrication processes may be utilized, as well, and the scope of the present invention is intended to encompass electrical coupling mechanisms for use with microcomponents irrespective of the fabrication process utilized to develop such mechanisms. Recent developments have allowed for fabrication of xe2x80x9creleasablexe2x80x9d microcomponents (e.g., stand-alone microcomponents that may be released or removed from the wafer). For example, the fabrication process disclosed in concurrently filed and commonly assigned U.S. patent application Ser. No. 09/569,330 entitled xe2x80x9cMETHOD AND SYSTEM FOR SELF-REPLICATING MANUFACTURING STATIONSxe2x80x9d allows for fabrication of releasable microcomponents. Furthermore, such fabrication process also allows for the fabrication of electrically isolated microcomponents. Additionally, other fabrication processes may be developed in the future, which may also allow for releasable microcomponents.
The electrical coupling mechanisms disclosed herein are suitable for coupling such releasable, stand-alone microcomponents. Of course, the electrical coupling mechanisms of the present invention may be implemented for any type of microcomponent, including both released and non-released microcomponents, and any such implementation is intended to be within the scope of the present invention. Given that such releasable microcomponents have only recently become possible, little advance has been made in the prior art toward electrical coupling mechanisms that are suitable for such releasable microcomponents. Releasable microcomponents may in some implementations have characteristics that should be taken into account in electrically coupling the microcomponents, which have not been an issue in the non-releasable microcomponents common in the prior art,. For example, releasable microcomponents may move in relation to each other (i.e., translate and/or rotate in relation to each other), and an electrical coupling should be utilized to allow for such desired movement.
Additionally, releasable microcomponents may be implemented in a manner such that the components are coupled out-of-plane with respect to each other, whereas non-releasable microcomponents of the prior art are generally only coupled in-plane (i.e., in the plane of the wafer of the microcomponents). Accordingly, electrical coupling mechanisms may be utilized to form an out-of-plane electrical coupling between two or more microcomponents. The electrical coupling mechanisms disclosed herein are suitable for use in various implementations of releasable microcomponents. For example, a ribbon cable, electrical connector, and/or a Z clamp connector may be utilized in electrically coupling such releasable microcomponents. For instance, the electrical coupling mechanisms disclosed herein may be implemented to allow for two or more microcomponents that move relative to one another to be electrically coupled. The electrical coupling mechanisms of the present invention may also be utilized to allow microcomponents to be electrically coupled in-plane or out-of-plane. For example, the electrical coupling mechanisms may be utilized to enable an electrical connection between microcomponents that are pulled off a wafer and coupled at 90 degrees to each other.
It should be appreciated that a technical advantage of one aspect of the present invention is that electrical coupling mechanisms suitable for electrically coupling microcomponents are provided. Another technical advantage of one aspect of the present invention is that electrical coupling mechanisms may be implemented to enable a relatively small-scale coupling between two or more microcomponents. For example, electrical coupling mechanisms disclosed herein may be implemented in a manner such that the coupling mechanism does not consume a disproportionately large amount of area in relation to the coupled microcomponents, as is common with the external wiring commonly implemented in prior art coupling techniques. A further technical advantage of one aspect of the present invention is that a flexible electrical coupling mechanism that is capable of adapting to various positions to enable microcomponents to be flexibly coupled is disclosed. For example, a ribbon cable is disclosed which may be implemented to provide a desired flexible electrical coupling between two or more microcomponents. In some implementations, bond pads may still be utilized to provide an electrical coupling, although the flexible electrical coupling mechanisms disclosed herein, such as a ribbon cable, enable for an electrical coupling between two or more microcomponents that is not physically attached to the substrate, as with prior art implementations.
Still a further technical advantage of one aspect of the present invention is that an electrical coupling mechanism is disclosed which enables an engageable/disengageable electrical connection between two or more microcomponents. For example, a Z clamp is disclosed which may be utilized to engage and disengage an electrical connection with a microcomponent, as desired. Accordingly, electrical coupling mechanisms are disclosed that enable an electrical connection to be achieved between two or more microcomponents in an unobtrusive manner. Yet a further technical advantage of one aspect of the present invention is that electrical coupling mechanisms are disclosed, which are suitable for electrically coupling microcomponents that are releasable/removable from the wafer (xe2x80x9creleasable microcomponentsxe2x80x9d).
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.